2. (Anat. & Zo["o]l.)
(a) Of or pertaining to the segments of animals; as, a
segmental duct; segmental papill[ae].
(b) Of or pertaining to the segmental organs.
{Segmental duct} (Anat.), the primitive duct of the embryonic
excretory organs which gives rise to the Wolffian duct and
ureter; the pronephric duct.
{Segmental organs}.
(a) (Anat.) The embryonic excretory organs of vertebrates,
consisting primarily of the segmental tubes and
segmental ducts.
(b) (Zo["o]l.) The tubular excretory organs, a pair of
which often occur in each of several segments in
annelids. They serve as renal organs, and often, also,
as oviducts and sperm ducts. See Illust. under
{Sipunculacea}.
{Segmental tubes} (Anat.), the tubes which primarily open
into the segmental duct, some of which become the urinary
tubules of the adult.